とある環境を用意したいので、ubuntuのdockerコンテナを作成。
Dockerfileに記述して、ビルド
すると、エラーが発生。
$ docker-compose build
........
省略
........
#0 166.6 Ign:7 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 Packages
#0 226.7 Ign:7 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 Packages
#0 286.7 Ign:7 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 Packages
#0 287.3 Ign:7 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 Packages
#0 287.6 Err:7 http://ports.ubuntu.com/ubuntu-ports focal/universe arm64 Packages
#0 287.6 Connection failed [IP: 185.125.190.36 80]
#0 287.7 Fetched 9407 kB in 4min 47s (32.7 kB/s)
#0 287.7 Reading package lists...
#0 287.8 E: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/focal/universe/binary-arm64/Packages Connection failed [IP: 185.125.190.36 80]
#0 287.8 E: Some index files failed to download. They have been ignored, or old ones used instead.